Psychological therapy services need to recognise that anxiety disorders tend to follow a chronic course and that good outcomes with CBT over the short term are no guarantee of good outcomes over the longer term. Clinicians who go beyond standard treatment protocols of about 10 sessions over a 6-month period are unlikely to bring about greater improvement. Poor outcomes over the long term are related to greater complexity and severity of presenting problems at the time of referral, failure to complete treatment irrespective of modality and the amount of interim treatment during the follow-up period. The relative gains of CBT are greater in anxiety disorders than in psychosis. Longitudinal research designs over extended periods of time (2-5 years), with large numbers of participants (500+), are required to investigate the relative importance of patient characteristics, therapeutic alliance and therapist expertise in determining the cost-effectiveness of CBT in the longer term.